Low humming noise and slight vibration coming from right rear

Stella87 · Post by **Stella87** » Wed Dec 28, 2016 9:51 pm

Hey all, set out to do my transmission fluid the other morning and that same morning my van started making an awful clanking or clunking noise if you will, intermittently coming from the rear, like metal was catching against metal. I had a family member drive it forwards and backwards while I tried to identify where exactly it was coming from but I couldn't figure it out. I have been worried that it was the rear diff, but after a good drive the diff isnt heating up too much and from my understanding these l300 diffs rarely fail. Over the last couple days it has developed a decently loud low humming noise coming from the rear of the vehicle and a slight vibration. progressively got worse over the day. I had a friend drive with me and listening from the inside of the van he says he thinks it is definitely originating from the right rear of the vehicle. Any time I am driving over ~60 kph or accelerating or engine breaking over those speeds that low humming noise and vibration is there and seems to get increasingly louder with speed , but the noise does subside while coasting downhill. I havent had time to jack up the rear and see if the wheel has any play in it or pulled the wheel and dug into it yet but im wondering if you guys have any pointers on where to begin looking or had a similar experience. TYIA

helibrian · Post by **helibrian** » Thu Dec 29, 2016 11:42 pm

I'm thinking exhaust.

Stella87 · Post by **Stella87** » Fri Dec 30, 2016 10:36 am

helibrian wrote:I'm thinking exhaust.

I have 2.5 inch side exit but did inspect that from outside when it initially happened... it's definitely not the exhaust.

sk66 · Post by **sk66** » Sat Dec 31, 2016 11:19 am

Keep driving it...eventually you will find out what's going bad

.

Killbert · Post by **Killbert** » Mon Jan 02, 2017 12:27 pm

Stella87 wrote:Hey all, set out to do my transmission fluid the other morning and that same morning my van started making an awful clanking or clunking noise if you will, intermittently coming from the rear, like metal was catching against metal. I had a family member drive it forwards and backwards while I tried to identify where exactly it was coming from but I couldn't figure it out. I have been worried that it was the rear diff, but after a good drive the diff isnt heating up too much and from my understanding these l300 diffs rarely fail. Over the last couple days it has developed a decently loud low humming noise coming from the rear of the vehicle and a slight vibration. progressively got worse over the day. I had a friend drive with me and listening from the inside of the van he says he thinks it is definitely originating from the right rear of the vehicle. Any time I am driving over ~60 kph or accelerating or engine breaking over those speeds that low humming noise and vibration is there and seems to get increasingly louder with speed , but the noise does subside while coasting downhill. I havent had time to jack up the rear and see if the wheel has any play in it or pulled the wheel and dug into it yet but im wondering if you guys have any pointers on where to begin looking or had a similar experience. TYIA

The L300 uses a greasable, yet sealed bearing. It has an innner and outer wheel seal. The inner seal prevents gear oil from exiting into the bearing assembly and out of the differential tube between the backing plate. The outer seal goes in front of the bearing and behind the spindle to protect the bearing from dust. I have ZERO clue as to why they sealed the bearing instead of having given it free flowing gear oil for lifetime lubrication. The service manual says to pack the bearing before install; however install requires the use of a press and it is very cumbersome. I paid a machine shop to finish the job after I spend a better part of 3 hours chiseling off the bearing backing collar thingy. No fun. So basically, you have to remove the bearing/spindle/brake shoe assembly in order to even attempt to grease the bearing. Furthermore, it's very difficult to effectively grease the bearing as you can only see the back of the bearing cage once you seperate the aforementioned assembly. The reason as to why I have explained all of this is to more or less single out that bearing as being the culprit of the noise, due to it's design. You can confirm bearing failure by driving down the road at about 45mph and swooping the truck from one direction to another. This will "load" the bearing and will cause it to sing loudly. If you turn the wheel to the left, throwing weight onto the right bearings, you will hear them make noise. The same goes for the opposite direction. This is what I recommend you do to confirm your suspicions. If your bearing is failed, I have part numbers for aftermarket US available equivalents and I would then highly recommend you drop the entire assembly off at a machine shop for a quick swap.

K

Post by **Growlerbearnz** » Tue Jan 03, 2017 9:46 pm

(Some?) pre-1990 Delica axles have open bearings with the bearing retained to the driveshaft with a nut. I presume they moved to the pressed-on retainer because cutting a thread into a drive shaft is super dodgy.

Stella87 · Post by **Stella87** » Wed Jan 04, 2017 10:56 am

Killbert wrote:
The L300 uses a greasable, yet sealed bearing. It has an innner and outer wheel seal. The inner seal prevents gear oil from exiting into the bearing assembly and out of the differential tube between the backing plate. The outer seal goes in front of the bearing and behind the spindle to protect the bearing from dust. I have ZERO clue as to why they sealed the bearing instead of having given it free flowing gear oil for lifetime lubrication. The service manual says to pack the bearing before install; however install requires the use of a press and it is very cumbersome. I paid a machine shop to finish the job after I spend a better part of 3 hours chiseling off the bearing backing collar thingy. No fun. So basically, you have to remove the bearing/spindle/brake shoe assembly in order to even attempt to grease the bearing. Furthermore, it's very difficult to effectively grease the bearing as you can only see the back of the bearing cage once you seperate the aforementioned assembly. The reason as to why I have explained all of this is to more or less single out that bearing as being the culprit of the noise, due to it's design. You can confirm bearing failure by driving down the road at about 45mph and swooping the truck from one direction to another. This will "load" the bearing and will cause it to sing loudly. If you turn the wheel to the left, throwing weight onto the right bearings, you will hear them make noise. The same goes for the opposite direction. This is what I recommend you do to confirm your suspicions. If your bearing is failed, I have part numbers for aftermarket US available equivalents and I would then highly recommend you drop the entire assembly off at a machine shop for a quick swap.

K

Exactly the help I was looking for, thanks a million!

Killbert · Post by **Killbert** » Wed Jan 04, 2017 11:49 am

No problem

Stella87 · Post by **Stella87** » Wed Jan 04, 2017 3:34 pm

Killbert wrote:No problem

Can you post those parts numbers?

Post by **Growlerbearnz** » Wed Jan 04, 2017 4:35 pm

http://www.delica.ca/forum/viewtopic.php?f=16&t=17210

Killbert · Post by **Killbert** » Wed Jan 04, 2017 5:35 pm

Stella87 wrote:
Killbert wrote:No problem
Can you post those parts numbers?

Will do

Sent from my SAMSUNG-SM-G891A using Tapatalk

Stella87 · Post by **Stella87** » Sat Jan 07, 2017 2:27 pm

So the noise is not more audible when going 45 mph and swerving left to right it's just over all loud and consistent st those speeds unless I'm off the throttle. Quote to repackage that inner bearing is 350 usd. I don't have the garage do pull the hub myself so I'm left to the mercy of the local shops. The vibration seems worse than before. Any other tips to isolate the noise or pinpoint this issue?

Post by **Growlerbearnz** » Sat Jan 07, 2017 2:38 pm

If you haven't already, I'd remove the rear wheels and look for anything amiss. A bearing that's failed enough to vibrate will often cause an oil leak, so look for oil where it shouldn't be (like dripping out the backplate). Look for evidence of rubbing or movement- compare both sides. It might even be something stuck in the wheel (which would be an awesome and easy fix!). Try pushing and pulling on the wheel while it's in the air- it should be solid, and not clunk or move in or out. Maybe remove the brake drums and see if anything is damaged inside- it should be uniformly dry and dusty in there.

I'm also wondering if your rear driveshaft has failed in some way- a universal joint bearing gone, perhaps. Try twisting, pushing, and pulling the driveshaft and feel for any clunking or movement that shouldn't be there. Wear gloves- it's usually disgustingly greasy. (I know the sound is coming more from the right rear, but the left rear has the heavy gas tanks hanging from it- any vibration that goes through the body will be louder on the right.)

Does the pitch of the humming change with road speed? A failed bearing will get louder the faster you go, but the pitch stays about the same. The vibration and noise from an unbalanced driveshaft or wheel will increase in pitch as well as volume the faster you go.

Good luck!

Killbert · Post by **Killbert** » Sat Jan 07, 2017 5:33 pm

Growlerbearnz wrote:If you haven't already, I'd remove the rear wheels and look for anything amiss. A bearing that's failed enough to vibrate will often cause an oil leak, so look for oil where it shouldn't be (like dripping out the backplate). Look for evidence of rubbing or movement- compare both sides. It might even be something stuck in the wheel (which would be an awesome and easy fix!). Try pushing and pulling on the wheel while it's in the air- it should be solid, and not clunk or move in or out. Maybe remove the brake drums and see if anything is damaged inside- it should be uniformly dry and dusty in there.

I'm also wondering if your rear driveshaft has failed in some way- a universal joint bearing gone, perhaps. Try twisting, pushing, and pulling the driveshaft and feel for any clunking or movement that shouldn't be there. Wear gloves- it's usually disgustingly greasy. (I know the sound is coming more from the right rear, but the left rear has the heavy gas tanks hanging from it- any vibration that goes through the body will be louder on the right.)

Does the pitch of the humming change with road speed? A failed bearing will get louder the faster you go, but the pitch stays about the same. The vibration and noise from an unbalanced driveshaft or wheel will increase in pitch as well as volume the faster you go.

Good luck!

Growler has it right. I'd have the differential drained into a catch Pan after a drive and have the fluid closely inspected for metal. Sounds to me like your differential is going south.

K

Killbert · Post by **Killbert** » Sun Jan 08, 2017 7:47 pm

You'll need these:

MB837719 - Inner Axle Seal (closest to differential) This is what leaks gear oil into what is designed to be a sealed, yet packed bearing. Stupid, stupid, stupid design.
MB092440 - axle o ring
MB664448 - The bearing retainer. This is pressed on and needs to be CHISELED off per Mitsubishi repair manual. F*CK that, I've been there. Find a machine shop with the tooling to press the bearing and bearing retainer off in one shot. This will save you or a crappy machine shop LOTS of headache and money. If they can press it off, they can reuse it.
MB664447 - Da bearing
MB092437 - Outer Axle seal. More like a dust seal. If fluid is coming out of this seal, you have a failed inner axle seal also.

Note: This is all pertaining to a 1991 and later. IF you have an earlier van, you may have different parts.

Another Note: I recommend removing the axle assembly and bringing it to a machine shop with your new parts in hand. Now remind you, you're going to be staring at an axle, brake shoes, wheel cylinder, and backing plate all together as an assembly. Basically, you disconnect the parking brake, the brake line fitting, and the 4 of the backing plate retaining nuts on the back of the axle tube.

My suggestion to double check? Partsfan.com

K